I have no remorse at all, I have vario panniers, and a full exhaust system, and an aftermarket screen, and lots of other bits and bobs. I don't regret any of them.
I don't think any of them are totally necessary, and it's a good bike to begin with, but I like to personalise all my bikes. The forks and shock upgrades were the most recent (and most expensive), but they are also my personal favourite.
I took the bike out today on some of my favourite b roads around the scottish borders, and I'm not a bike journo so I can't really describe perfectly how the brakes feel better because the suspension reacts better under braking, or how the feedback from the front wheel gives so much more confidence for cornering, comfort is better too, without spending £300ish on a new seat, so that's another saving
I like to ride relatively fast,one up, on twisty roads, so in my mind these are the most practical modification I've made.